Electrode for chromium plating



April 29, 1952 L. 6. DE QUASIE El'AL 2,594,381

ELECTRODE F OR CHRQMIUM PLATING 7 Filed Dec. 28, 1949 M arromvsr Patented Apr. 29, 1952 ELECTRODE FOR CHROMIUM PLATING Lacy Glenn De Quasie and Richard F. Eisenberg, Rochester, N. Y., assignors to Rochester Lead Works, Inc., Rochester, N. Y., a corporation of New York Application December 28, 1949, Serial No. 135,429

1 Claim. (01. 204-286) This invention relates to an electrode such as used as an anode in chromium plating by electrolysis, and it has for its purpose to afford an electrode that is easier and more economical to produce, more durable, and which possesses greater electrical efficiency than heretofore.

Such electrodes when made from lead or a lead mixture for chromium plating have consisted of a lead body portion that extends into the chromic acid bath and a hook portion of copper that is burned or soldered to the lead body, and it is a particular purpose of the invention to make the entire electrode of the same material and to form the hook or suspending portion which rests ona conducting rod integral with the body portion, thus avoiding the necessity of burning a copper hook portion on to a body portion, and also affording a more efficient contact or engagement with the conducting rod.

It is another purpose of the invention to construct the electrode in such a way that the hook portion retains its original form and does not straighten when carrying the'weight of the body portion, despite the relative softness of the lead body while at the same time providing a structure that maintains good electrical contact with the conducting rod, possesses a high degree of efficiency, and presents a maximum conducting surface to the chromium bath.

An .additional advantage of the invention lies in the initial lower cost of manufacture and the higher scrap-va1ue of the electrode after it has been used to maximum capacity, owing to the entire structure including the body portion and suspending hook portion being formed of an integral metallic body, and also the fact that the chromic acid in the bath does not afiect the lead hook portion when splashed thereon, whereas the hook portion is of copper and attached to a lead body portion, the acid from the bath attacks and is destructive of the copper hook portion which must be protected in some way.

To these and other ends, the invention consists in the construction that will appear clearly from the following description when read in conjunction with the accompanying drawings, the novel features being pointed out in the claims following the specification.

In the drawings:

Fig. 1 is a View in front elevation of a lead anode constructed in accordance with a preferred embodiment of the invention, partially broken away;

Fig. 2 is a view in side elevation of the same.

partially broken away, and showing in section the conducting rod on which the anode is supported;

Fig. 3 is a view in rear elevation, partially broken away;

Fig. 4 is a detail transverse sectional view on line 44 of Fig. 2 looking in the direction indicated, an

Fig. 5 is a transverse sectional view on line 5-5 of Fig. 1 looking in the direction indicated.

. The invention may be used in the manufacture of an electrode or anode formed of lead, or lead combined with approximately six per cent antimony or approximately seven per cent tin, or other strengthening and acid-resisting agent combined with the lead, as in the manufacture of conventional lead anodes, and the lead mass is first extruded in any convenient way to afford a body portion l which is relatively thin and preferably about thick from front to back at its outer edges and relatively wide, preferably about 3" in width, the body portion being provided with a central rib or flange 2 and outer ribs or flanges 3 located as shown and spaced equally from the center rib 2 and from the side edges of the body.

Such construction as just described is not feasible or practical if the hook portion is formed integrally with the body portion of the anode, and the present invention has to do with a con- I struction that enables forming a hook portion integral with a body portion and imparts to the hook portion sufficient strength and resistance to bending so that it will not straighten or lose its original shape when the Weight of the body is suspended on the hook portion, while also aifording more efficient contact between the hook portion of the anode-and the conducting rod.

In order to accomplish these purposes, the surfaces on the front of the body portion between the outer ribs 3 and-the center rib 2 are inclined slightly inwardly so that at the center of the anode adjacent to the central rib 2, the body por tion is approximately A," thick between the back surface 4 and the inner ends of the inclined surfaces 5, thus giving increased strength and resistance to bending at the center of the body portion throughout its length.

Such strengthening of the lead body at its central area may not be entirely sufiicient for the purpose and in order to impart greater resistance to bending, the body is provided on its back with a transversely arcuate enlargement or bead 6 extending throughout the length of the rear face of the anode, such enlargement 5 being preferably formed with a radius and with a distance of between the innermost point of-the enlarge- Jment 6 and the back surface 4 of the body portion measured perpendicularly to the latter along the radius about which the arc is struck to form the surface 6.

It will be understood that the first step in constructing the anode is to form a body having a cross-section as illustrated in Fig. by extruding a lead mass, such extrusion being accomplished by a suitably shaped die and a conventional extruding process. The body thus formed which may be of any desired length is of the shape illustrated in Fig. 5 in cross-section from end to end and also straight endwise, and it is then necessary to form the suspending hook portion at the upper end of the body for supporting the anode on the conducting rod indicated at T.

This is accomplished by first cutting one end of the body to form the inclined surfaces 8 and 9 and a reduced end portion defined by the side edges I6 and II, after which the reduced end portion is bent in any suitable manner to the shape illustrated in Fig. 2 defined by the upwardly and outwardly curved portion [2, the upwardly and inwardly bent portion l3, and the downwardly and inwardly bent terminal portion Hi. When the suspending hook portion. is thus formed, the anode is supported on the conducting rod 1' in the manner illustrated in Fig. 2.

When in this position, electrical contact is made at two points between the conducting rod 1 and the innermost portion of the arcuate enlargement 6 which extends endwisethroughout the hook portion. and constitutes a part of the upwardly and downwardly extending portions [3 and [4 that support the anode through the arcuate enlargement 6. With this arrangement, the arcuate enlargement 6, the innermost part of which rests against the conducting rod I at two points beneath the upwardly and downwardly extending portions l3 and I4, affords a point contact between the conducting rod and the anode, thus resulting in better conductivity and electrical efiiciency between the lead anode and the conducting rod support l. The arcuate enlargement 6 also affords additional strength in the anode at its central portion transversely or intermediate its side edges, sufiiciently to enable the suspending hook portion to retain its original shape after being formed, and to resist any tendency of the hook portion to straighten when subjected to the weight of the body of the anode suspended therebeneath.

Any tendency of the hook portion to straighten is further resisted and successfully overcome by the inclined surfaces 5 which afi'ordincreased thickness of the anode. at its central portion oppositely to. the. arcuate. enlargement 6 and. afford sufiicient stiffness for the contemplated purpose withoutv measurably reducing the conductive surface on the front. of the anode which contacts the chromic acid bath. It will be understood that the arcuate enlargement 6 and inclined surfaces 5 which afford the thickened area at the center of the anode extend throughout both the body and suspending hook portions of the anode, as illustrated in Figs. 4 and 5.

While the invention has been described with reference to the particular construction herein illustrated, it is not necessarily confined to the exact details disclosed, and this application is intended to cover such modifications or departures as may come within the purposes of the improvement and. the scope of the following claims.

Weclaim:

A one-piece lead-containing chromium plating anode comprising a relatively wide and thin body portion approximately 3" wide and thick and a single suspending hook portion of the same material as the body portion and of less width than the body portion, the body portion and hook portion having a continuous rib extending endwise and centrally thereof on their frcnt'and the body portion having outer'ribs extending endwise thereof on its front and spaced from said central rib and-from the side edges, the surfaces on said body and hook portions adjacent to the central rib being inclined from said central rib inwardly toward the side edges of the hook portion and toward the outer ribs of the body portion, and the back of the'body and hook portions having an arcuate enlargement extending. endwise and centrally thereof, the anode having a minimum thickness throughout of approximately 1 5" and the hook portion being resistant to bending.

LACY GLENN DE QUASIE. RICHARD F. EISENBERG.

REFERENCES CITED The following references are of record. in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,019,588 Beach Mar; 5', 1912 1,833,806 Weber Nov. 24, 1931 2,125,037 Sykes July 26, 1938 2,331,320 Hartzel Oct. 12, 1943 FOREIGN PATENTS Number Country Date 1,769 Great Britain of 1882 OTHER REFERENCES Canning "PracticalI-Iandbook on Electroplating, 11th ed., 1932, page 83.. Published by Canning Co. Ltd, Birmingham. England. 

